Tuesday, 30 April 2013

The season progresses

It's very interesting that at the very time when I'm photographing queen bumblebees, the EU has been trying to decide whether or not to ban or curb the use of neonicotinoid based insecticides. The most recent vote was indecisive, with UK voting against a ban and Ireland abstaining. But despite those disappointing votes, a two year ban has been implemented. I'd say the trial ban with a review in a couple of years certainly won't further damage the chances of our bees (and hoverflies!) surviving. It will, however, damage the profits of large, wealthy (and hence influential) producers, so I can guess where the pressure is coming from. Sooner or later we will all wake up and realise that we haven't got any food because the pollinators are all dead. 

The fourth of my queen bumblebees of the year is Bombus pascuorum:
Queen Bombus pascuorum - Common Carder Bumblebee
These are among the later of our local bumblebees to emerge, after B. lucorum s.l., B. terrestris and B. pratorum. I rarely see the queens of B. pascuorum, whilst it is relatively common to see the other queens hunting along hedgerows looking for a nesting spot. This is probably due to the fact that B. pascuorum is a surface-nesting species and the queen can therefore choose her nesting-spot relatively quickly.

The s.l. (sensu lato) after Bombus lucorum indicates that this is actually a complex of at least 3 species: B. lucorum, B. magnus and B. cryptarum. These three species are extremely difficult to separate when looking at anything other than queens. It seems that B. cryptarum is an upland, western species, B. magnus appears to prefer heathland and B. lucorum s.s. (sensu stricto) is a lowland species.

The reference is:

Niche differentiation of a cryptic bumblebee complex in the Western Isles of Scotland
JOE WATERS, BEN DARVILL, GILLIAN C. LYE and DAVE GOULSON School of Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA, UK

I managed to get a shot of a queen 'lucorum' this morning:

Bombus cryptarum queen nectaring (empty pollen baskets)
My local specimens of the lucorum complex all seem to be B. cryptarum, since they always show the distinctive thin line through the collar as indicated in this close-up:

Bombus cryptarum queen, showing the thin line through the yellow collar
That's how I'm recording them for the moment, anyway.

The 1k challenge is making me look much more closely at almost every specimen I see, and today I thought I  had found a new snail:

Cepaea nemoralis - Dark-lipped Banded Snail
So I keyed it out (height = width, > 8mm., no umbilicus, dark lip round aperture) and it turns out to be a common colour variant of the Dark-lipped Banded Snail - Cepaea nemoralis, which I've had before.

I took a few other shots, including this face shot, which shows the stalked eyes rather well:

Cepaea nemoralis, showing eyes
Preferred habitat is moist vegetation in cooler areas.

Going back to my initial moan about pesticides, I'm pretty sure that politicians are the wrong people to handle environmental issues: they are driven by short-term votes rather than thinking about longer-term issues. Is there some body or mechanism that can act outside government? If not, I fear that our wildlife is doomed to be a perpetually low priority.


The Weaver of Grass said...

There are plenty of 'agencies' which supposedly deal with these things Stuart - but the trouble is I suspect that many of the people who work for them are employed on the cheap and are not really qualified to deal with things. Lovely photographs - your country might be a lot wetter than ours but it is also much further on with Spring. Not even a hedge in leaf yet here.

Gill said...

That head shot of the snail is interesting - it seems to be short of a "tentacle" (what are they called, those sensory things they have under the eye stalks?) - presumably it had withdrawn it?

Things are just beginning to go green here. Good show of primroses and windflowers and I saw my first cowslips today.